1
WB JEE 2026
MCQ (Single Correct Answer)
+1
-0.25
Change Language

Let $f:(0,1) \rightarrow(0,1)$ be a differentiable function such that $f^{\prime}(x) \neq 0 \forall x \in(0,1)$ and $f\left(\frac{1}{2}\right)=\frac{\sqrt{3}}{2}$. Suppose for all $x$, $\mathop {\lim }\limits_{t \to x} \frac{\int_0^t \sqrt{1-(f(s))^2} d s-\int_0^x \sqrt{1-(f(s))^2} d s}{f(t)-f(x)}=f(x)$. Then the value of $f\left(\frac{1}{4}\right)$ belongs to

A

$\{\sqrt{7}, \sqrt{6}\}$

B

$\left\{\frac{\sqrt{7}}{2}, \frac{\sqrt{15}}{2}\right\}$

C

$\left\{\frac{\sqrt{7}}{4}, \frac{\sqrt{15}}{4}\right\}$

D

$\left\{\frac{\sqrt{7}}{3}, \frac{\sqrt{15}}{3}\right\}$

2
WB JEE 2026
MCQ (Single Correct Answer)
+1
-0.25
Change Language

If ' $a$ ' is an integer lying in $[-5,30]$, then the probability that the graph of $y=x^2+2(a+4) x-5 a+64$ lies above the $x-$ axis is

A

$\frac{1}{6}$

B

$\frac{7}{36}$

C

$\frac{2}{9}$

D

$\frac{3}{5}$

3
WB JEE 2026
MCQ (Single Correct Answer)
+1
-0.25
Change Language

Consider a square $A B C D$ of diagonal length 2a. The square is folded along the diagonal $A C$ so that the plane of $\triangle A B C$ is perpendicular to the plane of $\triangle A D C$. In this case the shortest distance between $A B$ and $C D$ is

A

$\frac{2 a}{\sqrt{3}}$

B

$\frac{a}{2 \sqrt{3}}$

C

$\frac{\mathrm{a}}{\sqrt{3}}$

D

$\frac{\sqrt{3} a}{2}$

4
WB JEE 2026
MCQ (Single Correct Answer)
+1
-0.25
Change Language

If $\int \frac{\left(1-x^2\right)}{\sqrt{x} \sqrt{\left(1+x^2\right)^3}}=\alpha \frac{x^\beta}{\left(1+x^2\right)^\gamma}+C ; \alpha, \beta, \gamma \in \mathbb{R}$ and $C$ is constant of integration, then $\alpha: \beta: \gamma$ will be

A

$4: 1: 1$

B

$2: 2: \frac{1}{2}$

C

$\frac{1}{6}: 2: \frac{1}{2}$

D

$1: 2: \frac{1}{2}$